1. Field of the Invention
This invention relates to an engine speed control system for a walk-behind truck.
2. Description of the Related Art
Common use is made of walk-behind trucks that are equipped with a bed for loading cargo and driven by the rotation of an engine transmitted to drive wheels, as taught by, for example, Japanese Laid-Open Patent Application No. 2003-312551. This type of truck is usually equipped with a clutch for transmitting the engine output to the driven wheels and the operator sets the truck in motion by engaging the clutch. Availability of sufficient power for driving the truck is ensured by using a mechanical governor or the like to maintain the engine speed in a high speed region for producing a high output. The truck taught by this reference is of the walk-behind type, i.e., of the type the operator walks behind while operating.
The engine of the conventional walk-behind truck is constantly operated at high speed. The stopped truck may therefore lurch (jackrabbit) when the clutch is engaged and cargo may be damaged or fall off as a result. Such a walk-behind truck is usually turned by discontinuing the supply of power to the driven wheel on one side to produce a difference in the rate of rotation between the left and right driven wheels. The walk-behind truck may therefore turn sharply when the power supply to one driven wheel is stopped with the speed of the engine maintained at a high level. This also may result in cargo being damaged or falling off. Constant operation of the engine in the high-speed range also increases fuel consumption and noise.